I found this really useful page on bitbucket of a collection of extension scripts made from various of people to enhance your Unity UI experience. Organized by this guy to keep it so neat and simple in your projects

A set of scripts built up from many examples for the Unity UI system.
Can be used either on their own or in collaboration with the new Unity UI system's source.
https://bitbucket.org/Unity-Technologies/ui

Including Radial menu like “rachet and clank”, SelectionBox for a RTS game where you can drag a selection of characters, simple ToolTip box, and draggable windows!
He has a youtube page that showcased many of these scripts here, Take a look:

Welcome to the Unity UI Extensions youtube site showcasing all the videos and training for all of the contributions provided by the community, carefully pack...

I’ve been using one that’s very helpful for inventory list with a vertical scrollbar. It’s autoscrolls to whatever you select. Great for gamepad’s d-pad support or arrowkeys XD
Spreading the love for all the devs!